In such systems, the hydraulic pressure is high, on the order of 3000 p.s.i. and it is important to isolate the coils of the electrohydraulic valve from the high pressure fluid. In addition, the hydraulic valve must be compact and have high magnetic efficiency.
In accordance with the invention, electrohydraulic valves for use in high fluid pressure systems such as automotive anti-skid brake systems, power steering systems and machine tool systems comprise a valve body of magnetic material, a valve seat member of magnetic material having a non-magnetic insert defining the seat and a coil surrounding a portion of the valve body and the valve seat adapted to be controlled by a microcomputer to provide pulses to a ball positioned between the valve seats and thereby control the flow through the valve. In one form the valve includes a second set of opposed valve seats, a second ball and a second coil. In each form, a sleeve surrounds the valve seats and the balls and hydraulically isolates them from the coil associated therewith.